(CNN) -- A Navy SEAL killed in a parachute training accident this week in Arizona belonged to the same elite squad that includes those chosen to go after Osama bin Laden in Pakistan two years ago, a source familiar with the matter said.

It was the second deadly military training accident in as many weeks and the third notable one in the United States since February. The other two killed 14 Marines combined in a mortar explosion and a helicopter collision.

The latest incident occurred around 12:30 p.m. local time on Thursday in a rugged part of the U.S. Special Operations Command facility at Pinal Airpark, military officials said on Friday.

Two sailors were undergoing a free-fall routine before opening their parachutes, a Navy official said in a statement, which added it was a normal exercise to maintain readiness.

One died from his injuries and another remained in stable condition on Friday at the University of Arizona Medical Center in Tucson, the Navy said.

It did not identify either and the accident is under investigation.

Lt. Cmdr. David McKinney, a spokesman for the Naval Special Warfare Command, did not reveal specifics but said the sailor who died "was assigned to an East Coast-based Naval Special Warfare unit."

A source with knowledge of matter said he was part of SEAL Team Six, members of which mounted the May 2011 operation that killed the al Qaeda leader in a third-floor bedroom of his compound in Abbottabad, Pakistan.

It was not clear whether or not he took part in the bin Laden mission.

The sailor who was injured was also a SEAL, the source said. But it was not clear whether he was part of the same East Coast group.